When is a Pitch Not a Pitch? (Roof Pitch)

If you are a sports fan, the first thing when you hear the term “pitch” has nothing to do with your roof. Your roof pitch can determine the type of roof on your home, the amount of rain gutter you need and whether a heating cable is necessary to protect your home from ice in the winter.

What does the pitch of a roof mean?

When you look at a roof, the pitch refers to the number of inches a roof rises for every 12 inches of depth. For instance, a roof with a 4/12 pitch means the roof rises 4 inches for every 12 inches you move toward the peak or ridge of the roof. The pitch can then be converted into degrees for an accurate measurement of the angle of your roof. Using our example of a 4/12 pitch, the roof would sit at an 18.5-degree angle.

What is the standard pitch for a roof?

While roofs vary from flat to steep depending on the architecture, building type and yearly average snowfall, the typical roof in the northeast sits at a 6/12 pitch or 26.6 degrees. However, a standard pitch can range from 4/12 pitch to 9/12 pitch without being considered either flat or steep. Homes located in areas that receive lots of rain or snowfall will have a greater pitch while buildings in temperate areas that do not see lots of moisture will typically have a lower pitch.

What is the least amount of pitch for a roof?

In the absence of a roof pitch, a roof is considered “flat.” However, flat roofs are never completely flat. They range in pitch from 1/24 pitch to 2/12 pitch to allow rain and snow to run toward gutters on the perimeter of the roof. A roof with between a 2/12 pitch and a 4/12 pitch is considered a “low slope” roof. These roofs are often made from special materials to make sure water does not seep into the structure.

What is the steepest pitch of a roof?

Anything above a 9/12 pitch is considered a steep roof. These roofs require additional fasteners on the rafters to keep them steady and additional fastening materials on roofing materials to keep them from shifting with heavy snow and ice loads or high winds. Since steep slope roofs are visible at street level, they lend themselves to architectural shingles, cedar shake shingles, slate tiles, or other attractive roofing materials.

This house has two roof pitches (on both levels). Again, we installed the roof.

How do you calculate a roof pitch?

In your attic access, position a level on the underside of one of your rafters, making sure your level is… well, level. At the 12 inch mark, measure the distance between the rafter and your level in inches. This number over 12 is your pitch.

If your roof has a simple gable, the measurement wall to wall will be twice the size of the run or the wall to the ridge horizontally. Divide the slope by two, and you will have the pitch.